Magnetically-operated switch.



PATENTED OCT. 31, 1905 G. H. HILL. MAGNETIGALLY OPERATED SWITCH.

APPLICATION FILED JUNE 18, 1904.

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UNITED STATES PATENT OFFICE.

GEORGE H. HILL, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRICCOMPANY, A CORPORATION OF NEIV YORK.

IVlAGNETlOALLY-OPERATED SWITCH.

Specification of Letters Patent.

Patented Oct. 31, 1905.

To all whmm it new concern.

Be it known that I, GEORGE E. HILL, a citizen of the United States,residing at Schenectady, in the county of Schenectady and State of NewYork, have invented certain new and useful Improvements inMagnetically-Operated Switches, of which the following is aspecification. I

My invention relates to magnetically-operated switches for electriccircuits, and has particular reference to magnetically-operatedcircuit-closers of the type known as contactors. In my patent, SerialNo. 762,4LO9, granted June 14, 1904, I have described a control systemfor electric motors employing a plurality of such contactors. In thissystem each contactor comprises a single magnet-coil and two switches inseparate motor-circuits arranged to be controlled by the single coil.This coil also controls contacts which in the first place establishproper connections for energizing the coil and when the coil isenergizedestablish a maintaining-circuit for the coil and also close the circuitfor the operating-coil of a second contactor. In such a system certaincharacteristics are particularly desirable in the construction of thecontactor. In the first place the contactor should form a compact unit,simple in operation and economical in construction. All live parts ofthe contactor, and particularly the moving parts, should be carefullyinsulated and inelosed. On the other hand, all parts should be readilyaccessible for inspection and repair. Contacts in the motor-circuitsshould be sufficiently heavy to carry the load and in closed positionshould make contact under strong pressure. Since the current in themotor circuit is large, suitable provision should be made forextinguishing the are when the contactor opens.

The object of'my present invention is to provide a suitable form ofconstruction for such contactors which shall meet the requirements aboveset forth, and to accomplish this end my invention comprises a number ofnovel features which will appear in the following specification andwhich are pointed out specifically in the appended claims.

My invention will {best be understood by reference to the accompanyingdrawings, in Which Figure 1 shows a side elevation, partly incross-section, ofa contactor constructed and arranged in accordance withmy invention. Figs. 2 and 3 show perspective views of the same. Fig. 4cshows a cross-section of the arc-chute employed in my contactor, andFig. 5 shows a detail of the contacts of the mot-orcircuits.

In the drawings, 1 represents the actuating- -coil of a contactorprovided with a movable core 2. The core 2 carries a spindle 3, whichsupports two sets of bridging members 4: and 5. hen the coil 1 isdeenergized and its core 2 is in its lowest position, as shown, thebridging member 5 is in engagement with the spring-contacts 6 6 andforms therewith the proper circuit connections for energizing coil 1. WVhen coil 1 is energized and core 2 is raised, bridging members 1 arebrought into engagement with the two sets of stationary spring-contacts7 7 and 8 8. It will be seen that bridging member 1 will engage thecontact 7 7 before bridging member 5 leaves the contacts 6 6. Bridgingmember 1, together with the contacts 7 7, form the maintainingcircuitfor the magnet-coil, and consequently this circuit is closed before thecircuit of the magnet-coil is broken. The contacts 8 8 close the circuitfor the operating-coil of the succeeding contactor. The specificconnections which have been here briefly outlined form no part of thepresent invention and are fully described in my former patent referredto above. The walls 33, which support the stationary contacts, serve toinclose and protect this position of the switch mechanism. hen coil 1 isdeenergized, core 2 is supported at its lower end by the support 9. Core2 carries at its lower end the pin 10, upon which is supported the shaft11. The shaft 11 is provided at each end with the insulating-bushings19., (shown in cross-section in Fig. 1,) and surrounding the bushings 12are metallic bushings 13. Loosely journaled on the bushings 13 atopposite ends of the shaft 11 are the links 14, which are pivoted at 15,as shown in Fig. 2. "heselinks 1.4: act to guide the shaft 11 when core2 is raised and lowered. Also loosely journaled on the bushings 13' ateach end of shaft 11 are the members 16, which carry themovable contacts17. This is clearly shown in Fig. 2. The contact 17, which may be formedof a single piece of rolled copper, is beveled, as shown, and is clampedto the member 16 by the clamp 22, member 16 being recessed to receivethe beveled edge of contact 17. This is shown in detail in Fig. 5.Engaging member 16 and holding it in the position shown is a spring 19,the other end of which carries the member 20, which is pressed by spring19 against the fixed abutment formed by the contact 21 and rubs thereonwhen the shaft 11 is raised and lowered.

18 represents the stationary contacts arranged to be engaged by themovable contacts 17 when the operating-coil is energized. The distancebetween contacts 17 and 18 is proportioned with reference to the travelof the core 2 of the operating-coil, so that the two contacts arebrought into engagement with each other before the core 2 reaches theupper limit of its travel. This has two results. In the first place thebuckling of spring 19, produced by the continued upward movement of thecore, results in a stronger pressure of the member 20 on the contact 21and of contact 17 on contact 18 and at the same time produces a rubbingof contact 17 on contact 18. Thus good contact is assured, not only bypressure, but by friction between the engaging surfaces of the contactsat which the circuit is made and broken.

23 represents insulating-covers which are hinged at 25 and are held inclosed'position by the spring-clips 24:. This is shown clearly incross-section in Fig. 1. These insulatingcovers serve to inclose thelive parts of the contactor which are included in the motorcircuit andat the same time may readily swing away, as shown in Figs. 2 and 3, topermit inspection and repair.

26 represents a blow-out coil which is provided with parallelpole-pieces 27, extending on opposite sides of both sets of contacts inthe motor-circuit.

The contacts 17 and 18 are curved away from each other at their tips, asshown, so that the arc in traveling outward along the contacts under theinfluence of the magnetic field produced by the pole-pieces 27 will belengthened, and consequently more easily ruptured. To inclose the areproduced be tween the contacts and to insulate the polepieces 27therefrom, I provide the arc-chute 28, formed of insulatingnon-combustible material. One of the arc-chutes 28 is shown incross-section in Fig. 4. It will be seen from this figure that thecentral portion of the arcchute is hollowed out to admit the tips of thecontacts 17 and 18, as shown in dotted lines in Fig. 1, and to provideboth a vertical and a horizontal chute for the arc. The sides of thearc-chute are extended by the wings 29, (shown in Fig. 4,) which extendinside of the pole-pieces 27 and serve to insulate them effectively fromthe arc and also to act as guides for moving the chute into and out ofposition. The arc-chute 28 is provided with supporting-bars 30, whichloosely engage the pole-pieces 27. The upper supporting-bars 30 areprovided with the pivoted links 31, the

ends of which are formed with an L-shztped slot which engages a pin 32on the pole 27. This construction holds the arc-chutes firmly in placeand yet permits ready removal for inspection and repair and supports thechutes in the removed position. Thus from an inspection of Fig. 1 itwill be seen that the weight of the chute, which is supported from thepin 32, tends to hold the chute in position and that it is impossible toslide the chute outward without raising the link 31. By raising the link31, however, so as to bring the other leg of the L-shaped slot intoengagement with pin 32, the arc-chute may be readily withdrawn into theposition shown in Fig. 3, affording access to the contacts. In thisposition the pin 32 still acts as a support for the arc-chute andprevents it from completely falling off. To further protect thepole-pieces from arcs, the ends may be coated with any suitableinsulating material, such as porcelain enamel.

Although I have shown a contactor designed particularly for use in thesystem of control described in my former application mentioned above, myinvention is not limited in all its features to use in this particularsystem. The arrangement of contacts may be varied, as desired, to meetthe different requirei'ncnts of a different system of control employingdifferent circuit connections. Such modifications will be obvious tothose skilled in the art, and I aim in the appended claims to cover allsuch modifications.

What I claim as new, and desire to secure by Letters Patent of theUnited States, is-

1. In combination, a magnet-coil, a movable core therefor, a shaftsupported by said core, pivoted links engaging opposite ends of saidshaft, and switch-contacts supported on opposite ends of said shaft.

2. In combination, a magnet-coil, a movable core therefor, a shaftsupported by said core, and spring-pressed switch-contacts looselyjournaled on opposite ends of said shaft and insulated therefrom.

3. In combination. amagnet-coil, a movable core therefor, a shaftsupported by said core, insulated bushings on said shaft, andspringpressed contacts loosely journaled on said bushings.

1. In combination, a magnet-coil, a movable core therefor, a shaftsupported by said core, a contact member loosely journaled on saidshaft, a spring, one end of which engages said contact member and theother end of which bears against a fixed abutment, and a stationarycontact adapted to be engaged by said contact member and so positionedthat said. spring is placed under tension when said core.

5. In combination, a magnet-coil, a movable core therefor, a shaftsupported by said core,

I a contact member loosely journaled on said member is moved to closedposition by said shaft, a fiat spring, one end of which engages saidcontact member and the other end of which presses against a fixedabutment, and a stationary contact adapted to be engaged by said contactmember and so positioned that it is engaged by said member when 'saidcoil is energized before said core reaches its closed position, wherebysaid spring is buckled and produces a wiping movement of said contacts.

6. In combination, amagnet-coil, a movable core therefor, a shaftsupported by said core, switch members supported at opposite ends ofsaid core, and hinged insulating-covers inclosing said members.

7. In combination, switch-contacts, a blowout coil therefor havingpole-pieces ex tending on opposite sides of said contacts, and aninsulating arc-chute removably supported between said pole-pieces andinclosing said con tacts.

8. In combination, switch-contacts, a blowout coil therefor havingpole-pieces extending on opposite sides of said contacts, an arcchuteinclosing said contacts, pivoted links carried by said chute, andpin-and-slot connections between said links and said polepieces, wherebysaid chute is removably supported between said pole-pieces.

9. In combination, switch-contacts, a blowout coil therefor havingpole-pieces extending on opposite sides of said contacts, an arcchuteinclosing said contacts, pivoted links carried by said chute and havingL-shaped slots at their ends, and pins on the pole-pieces adapted toengage said slots.

10. In combination, a magnet-coil, a movable core therefor, a membersupported by said core, switch-contacts supported at opposite ends ofsaid member, and a blow-out magnet located between said switch-contactsand having pole-pieces extending on opposite sides of bothswitch-contacts.

11. In combination, a magnet-coil, a movable core therefor, a membersupported by said core, switch-contacts supported at opposite ends ofsaid core, a blow-out magnet located between said switch-contacts, andparallel pole-pieces at opposite ends of said blowout magnet extendingon opposite sides of both switch-contacts.

In witness whereof I have hereunto set my hand this 17th day of June,1904.

GEORGE H. HILL.

Witnesses:

BENJAMIN B. HULL, HELEN ORFORD.

